A sphincter is a muscle that surrounds an opening, tube, or other vesel and serves to selectively close such a vessel. Sphincters are commonly associated with the bladder and urinary system, stomach entrances, and the anus. In each instance, the sphincter selectively opens and closes the vessel to respectively enable or inhibit the flow of a particular substance therethrough.
When the sphincter fails to operate, the art teaches various techniques for artificially performing the functions of the sphincter. Goldstein in U.S. Pat. No. 4,053,952, teaches the use of magnetism to control the flow of fluids. Reincke, in the U.S. Pat. Nos. 4,167,952 and 4,197,835 discloses a fluid inflatable cuff employed in a sphincter application.
In selectively opening and closing a vessel, a number of features appear desirable in an artificial sphincter should be capable of repetitive and controllable operation. That is, the vessel should be selectively opened and closed on demand. Second, the artificial sphincter should be implantable and hence body compatible. Third, it may also be desired to actuate the artificial sphincter remotely, or noninvasively, without the use of wires or the like. Fourth, it would also appear desirable to provide an artificial sphincter having minimal implanted parts and no fluids contained by the implant which would require leak-proofing, proper fluid selection, and/or other safety measures. Fifth, it would further appear desirable to provide an easily operated, reliable mechanism. Sixth, it would still further appear desirable to selectively open and close a vessel without a valve which requires proper seating and relative movement of parts.